FIG. 1. BEETLE (Chalcosoma Atlas). 

 Upper figure, male (reduced) ; lower figure, female {natural size). 



FIG. 2. FISH (Callionymus Lyra). 

 Upper figure, male ; lower figure, female. The lower figure is 



more reduced than the upper. 



(From "The Descent of Man," by C. Darwin.) 



5 



